The invention relates to a focusing structure of a binocular. The focusing structure comprises a binocular body with a middle shaft, a pair of objective lens barrels, a pair of objective lenses in the objective lens barrels respectively, a focusing handwheel, a focusing tube with outside threads, two transmission rods, two sliding barrels and two focusing lenses arranged in the sliding barrels respectively, one end of the focusing tube is fixedly connected with the focusing handwheel, the other end of the focusing tube is in threaded connection with the end, far from the objective lenses corresponding to the middle shaft, of the binocular body, the two sides, corresponding to the middle shaft, of the back or belly part of the binocular body are provided with chutes, the two transmission rods are placed in the corresponding chutes and can slide along the extension direction of the corresponding chutes respectively, the end, far from the objective lens, of each transmission rod bends towards the focusing tube and is connected with the focusing tube, the side, close to the corresponding transmission rod, of each objective lens is provided with a through slot, and the end, close to the objective lens, of each transmission rod is connected with the corresponding sliding barrel via a connecting rod which penetrates the through slot. The focusing structure of the binocular had the advantages of being convenient to assembly and low in production cost.